1. Field of the Invention:
This invention relates to improvements in sealing devices useful in flow conductors. More specifically, the invention relates to sealing devices or packers for wells, which may be positioned in a well flow conductor and operated to compress and expand an improved resilient sealing element carried on the device, into sealing engagement with the flow conductor. When sealingly engaged, the expanded sealing element functions as a cup type sealing element or packer
2. Description of Related Art
The following U.S. patents, all to J. W. Tamplen and incorporated herein for reference, disclose sealing devices using sealing elements provided with anti-extrusion members in the form of coil springs, molded into the elements at each end, to prevent pressure extrusion of the resilient sealing material and enable the sealing element and device to seal against higher pressures:
U.S. Pat. No. 3,215,208 patented Nov. 2, 1965
U.S. Pat. No. 3,227,462 patented Jan. 4, 1966
U.S. Pat. No. 3,278,192 patented Oct. 11, 1966
An U.S. Pat. No. 3,278,219, which issued to T. L. Elliston Oct. 11, 1966, discloses the use of a sealing element, having coil springs molded into each end to prevent extrusion, on a well tool for retrieving objects from a well.
Another U.S. Pat. No. 3,118,682, to John V. Fredd issued Jan. 21, 1964. This patent discloses the use of an expandable metal backup member at one end of an elastic seal member.
Another U.S. Pat. No. 2,988,148 issued June 13, 1961 to Martin B. Conrad and John F. Muse, discloses a packing element that when expanded into sealing engagement with a well conduit functions as a cup type seal or packer as an increase in pressure sealed causes the cup type seal to seal tighter. The cup type seal disclosed in this patent does not utilize coil springs in both ends to prevent extrusion of the sealing material.
The use of coil springs in the ends of expandable resilient sealing elements, to prevent pressure extrusion of the sealing material, has enabled sealing elements which function as cup packers when sealing to continue to seal when subjected to pressures high enough to cause failure of sealing elements having no coil springs.
Failure of sealing elements, which function as cup type seals and utilize coil springs to prevent pressure extrusion, have occurred in deep, hot hydrocarbon wells where the resilient sealing material has been softened by high earth temperatures and the pressure holding capabilities of these sealing elements have been exceeded. These failures cause loss of well production and could cause loss of well pressure control resulting in well blowout with possible damage to the well and well equipment and danger to property and lives.